1st marines went ashore in Guadalcanal with the 1903 a3. The army then renforced them with m1s. The fighting was still hot. When a Army wounded guy left the garand stayed. Wasn’t long after that the marines made it their battle rifle. Patton said the garand was the reason the US won the war. The marines1st was first in the garand was the last out.
The first M-1 Garands used in combat was by the 31st Infantry Regiment on Luzon, PI, in December, 1941, is one of the tidbits of history I learned from the US Army Center of Military History while working there. The sending of several thousand M-1’s to the Philippines during either late 1940 or early 1941 was one of the modernization of the US Army’s Philippine Division.